Various approaches to handling computers' energy requirements have been proposed in the past, including for example U.S. Pat. No. 5,964,879, Method and System for Dynamically Power Budgeting with Device Specific Characterization of Power Consumption Using Device Driver Programs, (Dunstan et al, Oct. 12, 1999) and U.S. Pat. No. 5,396,635, Power Conservation Apparatus Having Multiple Power Reduction Levels Dependent upon the Activity of the Computer System, (Fung, Mar. 7, 1995). However, these examples do not make good use of possibilities for energy storage, and do not address external variables such as energy prices.
Energy—related problems in computing include increasingly dense concentrations of computers, that may make existing electrical wiring inadequate in some buildings. Supplying adequate current to dense clusters of computers may be difficult and costly, especially considering the current required when computers are handling a peak work load. There are additional problems in some utility markets, where energy may have variable pricing, or where the reliability of the energy supply may be variable, depending on the time of day or other factors. There is a need for systems and methods that address such energy—related problems.